Figure 3

Structure analysis of the JIC Pisum Collection: Comparing different K values. The results of three Structure runs for K values of 3, 7 and 11 are shown, together with the means for 10 K = 3 runs and the 3 most reproducible K = 7 runs. For each run the fractional inferred ancestry of the 3029 individuals is plotted as a histogram, with each ancestral population colour-coded. Accessions are assigned to Sub-Group N if their average representation (Q_N) for that Sub-Group ≥ 0.5. Accessions in Groups 1 and 2 are ordered by decreasing Q and for group 3 by increasing Q. Admixtured accessions, where Q₁+Q₂ ≥ 0.5, are placed between groups 2 and 3, ordered by increasing Q₃. For K = 7 the accessions are ordered within Sub-Groups in a similar way. For K = 11 there was no consistent assignment between Structure runs of accessions to groups; therefore the accession order is the same as for K = 3 (see also Additional file 4). At the bottom of the K = 3 figure the fraction of missing data per accession is plotted as a black vertical bar.